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The replacement of gold bonding wire with silver bonding wire can significantly reduce the cost of wire bonding. This paper provides a comprehensive overview of silver wire bonding technology. Firstly, it introduces various types of silver-based bonding wire currently being studied by researchers, including pure silver wire, alloy silver wire, and coated silver wire, and describes their respective characteristics and development statuses. Secondly, the development of silver-based bonding wire in manufacturing and bonding processes is analyzed, including common silver wire manufacturing processes and their impact on silver wire performance, as well as the impact of bonding parameters on silver wire bonding quality and reliability. Subsequently, the reliability of silver wire bonding is discussed, with a focus on analyzing the effects of corrosion, electromigration, and intermetallic compounds on bonding reliability, including the causes and forms of chlorination and sulfurization, the mechanism and path of electromigration, the formation and evolution of intermetallic compounds, and evaluating their impact on bonding strength and reliability. Finally, the development status of silver wire bonding technology is summarized and future research directions for silver wire are proposed. [ABSTRACT FROM AUTHOR]

Aiming to resolve the practical problem of brown rice kernels being easily broken due to overprocessing during processing (milling and polishing), brown rice kernels of Japonica rice, after hulling, were used as the research object in this study. Firstly, through a texture meter test, the discrete element bonding parameters (Kn is normal stiffness per unit area, Kτ is tangential stiffness per unit area, Cn is critical normal stiffness, Cτ is critical shear stiffness) were obtained. Secondly, a brown rice kernels' bonding particle model was established by EDEM, and then a second orthogonal rotational combination test was carried out to calibrate the discrete bonding parameters, Kn = 4.43 × 1012 N/m3, Kτ = 6.13 × 1011 N/m3, Cn = 2.55 × 107 Pa, and Cτ = 7.92 × 107 Pa. The error of parameter calibration was within 5%, and the results were able to reflect the actual situation more realistically. Finally, analysis of the crushing process of brown rice kernels showed that their ability to withstand shear damage was not as great as their pressure-bearing capacity. The design of the relevant mechanism and the setting of parameters should be based on the critical shear stiffness of brown rice kernels, and the actual shear force Fτ* set during the processing should be smaller than the theoretical critical shear force Fτ (Fτ* < Fτ = 9.11 N). This study can provide a theoretical basis for optimizing the key structure and operating parameters of rice milling machines and polishing machines to effectively solve the practical problem of increased crushing of brown rice kernels due to overprocessing. [ABSTRACT FROM AUTHOR]

There will be great damage in the process of harvesting, transporting, and storing after grain matures. The injury rate is as high as 8% to 12%. After damage, the germination rate of the grain becomes lower, the quality decreases, and it is easily infected with pests and molds. This study of the grain-crushing characteristics is of great significance to ensure grain quality, and an accurate crushing model is a prerequisite for effectively simulating crushing characteristics. This paper studies the shattering characteristics of wheat grains. Two-dimensional slices of wheat grain were obtained using X-ray tomography technology. Then, an accurate three-dimensional outer contour model of the wheat particle was constructed using image filtering and segmentation algorithms. The particle filling process was conducted using EDEM 2018 software to establish a wheat particle simulation model based on the Hertz–Mindlin with a Bonding contact model. Using the DOE experimental design method, single-factor experiments, Plackett–Burman experiments, steepest-climb experiments, and Box–Behnken were designed to study the fragmentation characteristics of wheat particles combined with parameter calibration and physical experiments. The test results show that the normal stiffness per unit area is 7.392 × 1010 N/m3, critical normal stress is 5.293 × 106 Pa, critical tangential stress is 5.001 × 106 Pa, and the relative error about 3%, which verifies the reliability of the simulation parameters in the discrete-element crushing model of wheat grain. This study focuses on two essential aspects: 1. establishing an accurate wheat-grain contour model; and 2. calibrating the bonding parameters of the discrete-element simulation model of wheat grain. The wheat grain discrete-element crushing model and the calibration of its bonding parameters are constructed to provide a foundation for the study of wheat-grain crushing characteristics. It is of great significance to study the situation of wheat grains and where cracks are produced. In this paper, an accurate model of the wheat-grain contour is established, and the bonding parameters of the discrete-element simulation model of the wheat grain are calibrated. The calibration of the model of the discrete elements of wheat-grain fragmentation and its bonding parameters will provide a basis for studying the crushing characteristics of wheat grain. Understanding the condition of wheat grains and the causes of cracks carries significant academic significance. [ABSTRACT FROM AUTHOR]

We report on the Sm3+ and Sm3+:Yb3+-doped barium fluorotellurite glasses prepared using the conventional melting and quenching method. The spectroscopic characterisations were investigated with Raman and FTIR to evaluate the glasses' structural and hydroxyl (-OH) content. The Raman analysis revealed a structural modification in the glass network upon adding and increasing the Yb3+ concentration from a TeO3 trigonal pyramid to a TeO4 trigonal bi-pyramid polyhedral. At the same time, the FTIR measurements showed the existence of -OH groups in the glass. Thus, under the current experimental conditions and nominal composition, the -OH group contents are too large to enable an effective removal. The near-infrared region of the absorption spectra is employed to determine the nephelauxetic ratio and bonding parameters. The average nephelauxetic ratio decreases, and the bonding parameter increases with the increasing Yb3+ content in the glasses. A room temperature visible and near-infrared photoluminescence ranging from 500 to 1500 nm in wavelength and decay properties were investigated for glasses doped with Sm3+ and Sm3+-Yb3+ by exciting them with 450 and 980 nm laser sources. Exciting the Sm3+- and Sm3+-Yb3+-doped glasses by 450 nm excitation reveals a new series of photoluminescence emissions at 1200, 1293, and 1418 nm, corresponding to the 6F11/2 state to the 6HJ (J = 7/2, 9/2, 11/2) transitions. Under the 976 nm laser excitation, a broad photoluminescence emission from 980 to 1200 nm was detected. A decay lifetime decreased from ~244 to ~43 μs by increasing the Yb3+ content, ascribing to concentration quenching and the OH content. [ABSTRACT FROM AUTHOR]

Oxyfluoride (P2O5-Bi2O3-Na2CO3-SrCO3-ZnF2-Eu2O3) glasses of different dopant (Eu3+) ion concentrations were synthesized by the traditional melt quenching method. Optical absorption, luminescence and lifetime measurements were performed with UV-Vis and PL techniques. A total of six absorption bands were observed in the wavelength range 200-800 nm, including one intense high band at 392 nm was assigned to 7F0→5L6 transition. The covalency between the host environment and Eu3+ ion was noticed with the measured nephelauxetic ratios (β) and bonding parameters (δ). The energies of the energy band gaps (Eg) and Urbach (ΔE) were estimated from the Tauc's plots, drawn from the absorption spectra. Luminescence spectra exhibited the prominent reddish-orange emission at 612 nm due to the 5D0→7F2 characteristic transition of Eu3+ ion. The lasing (radiative) parameters of f-f transitions of the Eu3+ ion was evaluated using the Judd-Ofelt intensity parameters (Ω2, Ω4, and Ω6). The higher magnitude of branching ratios (βexp) suggests the suitability of the present glass. The decay profile for the 5D0 level of europium was recorded by monitoring the emission and excitation wavelengths 612 & 392 nm, respectively. The color temperature and purity were calculated using CIE 1931 color coordinates. The emission color band spectra have also been recorded. [ABSTRACT FROM AUTHOR]

The glasses with the composition 20PbO-(10-x)CdO-10TeO -60B O -xCuO (0.5=x=2) were prepared by melt quenching technique. X-ray diffractograms revealed the amorphous nature of the glasses. Optical absorption spectra are recorded at room temperature. Optical band gap (E) and Urbach energies were determined. Electron Paramagnetic opt 2+ Resonance (EPR) studies were carried out by introducing Cu2+ as the spin probe. EPR spectra of all the glass samples were recorded at X-band (≈9.7 GHz) frequencies. From the EPR spectra spin-Hamiltonian parameters were evaluated. It -4 -1 -4 was observed that (g ≈2.360, g≈2.080) g >g >g (2.0023) and (A≈136x10 cm, A ≈30 x10-4 cm-1) A1 >A1. From these values it is concluded that the ground state of Cu2+ is (²Bfg) and the site symmetry around Cu ion was 1g tetragonally distorted in octahedral sites. It was observed that the intensity of the EPR spectra increases with increase of CuO concentration, which shows that more number of Cu ions are participating in the resonance. The optical absorption spectra revealed broad absorption band, which is assigned to transition. From the EPR and Optical 1g 2g data bonding coefficients were evaluated and discussed. [ABSTRACT FROM AUTHOR]

In the present research some bonding parameters of hypersensitive transition of Pr(III) doped systems with three ligands having amide group have been done. For this research we have choose four parameters such as nephelauxetic ratio (β ), bonding parameter (b1/2), Sinha's covalency parameter (δ%) and covalency angular overlap parameter (η). From the observed data of these parameters, it concludes that in the bonding between Pr(III) ion and amide group of ligands, the involvement of 4f-orbital has very less as compared to transition metals. In the present study we have also investigated the antibacterial activity of various doped systems. This antibacterial activity is investigated against the Escherichia coli and Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

A blue colored Cu-doped lead zinc phosphate glass in the system 10 PbO-30 ZnO-59.9 PO-0.1 CuO was prepared by quenching of the melt and spectral properties of these glasses were studied. Optical absorption and electron paramagnetic resonance spectra of Cu ion in these glasses were measured. Polarization produced by uneven distribution of d-electron density on the inner core of s-electron was studied. The estimated results showed that the g > g because Cu ions had tetragonally elongated distortion. Optical absorption studies also supported the same property. The variation in crystal field caused the change in bonding nature. The Fourier transform infrared spectra had elucidated the bonding system of the constituent atoms and groups that shed light on the expected structure. Raman spectra were used to get information about the depolymerization of phosphate chains in the glasses with successive replacement of alkali content. [ABSTRACT FROM AUTHOR]

In this paper, in order to improve the reliability of anisotropic conductive film (ACF) interconnections, solder ACF joints were investigated in terms of solder joint morphology. ACFs are film-type interconnection adhesive materials that consist of polymer adhesive resins and randomly dispersed conductive particles. Recently, in order to obtain high reliability of ACF joints, solder ACFs that use solder particles as conductive particles of ACFs have been introduced combined with an ultrasonic bonding method. However, further researches are needed in the area of crack initiation and the propagation of solder ACF joints at high temperature and high humidity conditions due to the stress generated by hygroscopic expansion of ACF resin. Therefore, in order to solve the crack initiation of solder ACF joints, solder ACF joint morphology should be controlled and optimized to minimize the solder crack-related reliability problems. In this paper, solder ACF joint reliability was investigated depending on the solder morphologies of ACF joints bonded with various bonding pressures and temperatures. According to the results, as bonding pressure increased from 2 to 6 MPa, aspect ratio (joint diameter/joint gap) increased due to the increased joint area and decreased joint gap. In the pressure cooker test (PCT) reliability tests, as solder aspect ratio increased, electrical resistances were more stable after 60 h of the tests due to higher joint strength. In the target bonding temperature profile of 250 °C, solder joints showed a concave shape. However, joints bonded at in the target bonding temperature profile of 200 °C showed a convex shape. It is mainly due to the lower degree of cure of resin when ACF temperature reached to solder Melting Point (MP) in the target bonding temperature profile of 250 °C compared with that in the target bonding temperature profile of 200°, because ACF temperature reached to solder MP in shorter time in the target bonding temperature profile of 250 °C. Concave-shaped solder joints showed higher PCT reliability than the convex-shaped solder joints due to the lower stress concentration. These results indicate that solder ACF joint morphology was a significantly important factor for highly reliable solder ACF joints in high temperature and high humidity reliability conditions. [ABSTRACT FROM PUBLISHER]

Cu(II) ion-doped NaCaAlPO4F3 phosphor has been synthesized using a solid state reaction method. The prepared sample is characterized by powder X-ray diffraction, scanning electron microscope, optical absorption, electron paramagnetic resonance photoluminescence and Fourier transform infrared spectroscopy techniques. The crystallite size evaluated from x-ray diffraction data is in nanometers. Scanning electron microscopy micrographs showed the presence of several irregular shaped particles. From optical absorption and electron paramagnetic resonance spectral data the doped Cu(II) ions are ascribed to distorted octahedral site symmetry. The synthesized phosphor exhibits emission bands in ultraviolet, blue and green regions under the excitation wavelength of 335 nm. The CIE chromaticity coordinates (x = 0.159, y = 0.204) also calculated for the prepared sample from the emission spectrum. The Fourier transform infrared spectroscopy spectrum revealed the characteristic vibrational bands of the prepared phosphor material. [ABSTRACT FROM AUTHOR]

Thermosonic flip-chip (TSFC) bonding is a flexible and rapidly developing package technology, in which ultrasonic energy is used to reduce bonding temperature, time, and force. In this paper, a laboratory TSFC bonder with a smooth end tool and without vacuum or a die collet was developed to bond a gold bump to a silver pad in order to understand the effect of ultrasonic energy on flip-chip bonding strength. With a laser Doppler vibrometer, the ultrasonic vibration of the tool and flip chip were measured during the bonding process. In addition, the energy loss between the tool and chip was observed. The relationship between energy loss, ultrasonic propagation, bump deformation, and bonding parameters was discussed. The effects of bonding parameters on bonding strength and vibration transferred from the tool to chip were experimentally investigated. Results show that energy losses prevent over-bonding phenomenon caused by an excess of ultrasonic power. Good bonding strength can be achieved by optimizing bonding parameters using a tool without a vacuum or collet. Compared to vacuum-based or groove tools, smooth-end tools are able to automatically control the ultrasonic energy applied at the bonding interface. [ABSTRACT FROM AUTHOR]

Pure and copper doped glasses with composition, xLi2O-(40-x)Na2O-50B2O3 -10Bi2O3, have been prepared over the range 0 ≤ x ≤ 40. The electron paramagnetic resonance (EPR) spectra of Cu2+ ions of these glasses have been recorded in the X-band at room temperature. Spin Hamiltonian parameters have been calculated. The molecular bonding coefficients, α2+ and β2+, have been calculated by recording the optical absorption spectra in the wavelength range 200--1200 nm. It has been observed that the site symmetry around Cu2+ ions is tetragonally distorted octahedral. The density and glass transition temperature variation with alkali content shows non-linear behaviour. The IR studies show that the glassy system contains BO3 and BO4 units in the disordered manner. [ABSTRACT FROM AUTHOR]

A reliable copper wafer bonding process condition, which provides strong bonding at low bonding temperature with a short bonding duration and does not affect the device structure, is desirable for future three-dimensional (3-D) integration applications. In this review paper, the effects of different process parameters on the quality of blanket copper wafer bonding are reviewed and summarized. An overall view of copper wafer bonding for different bonding parameters, including pressure, temperature, duration, clean techniques, and anneal option, can be established. To achieve excellent copper wafer bonding results, 400°C bonding for 30 min. followed by 30 min. nitrogen anneal or 350°C bonding for 30 rein. followed by 60 min. anneal bonding is necessary. In addition, by meeting the process requirements of future integrated circuit (IC) processes, the best bonding condition for 3-D integration can be determined. [ABSTRACT FROM AUTHOR]

Aluminium metal matrix composites (AlMMCs) offer several advantages relative to monolithic aluminium alloys such as high stiffness, strength, wear resistance, low thermal expansion coefficient, etc. However, despite considerable improvements in developing AlMMCs, the lack of reliable joining methods restrict their greater application. Fusion welding of AlMMCs has not proved successful because high temperature nature of the process normally causes unfavorable reactions between the reinforcement and the matrix, leading to the formation of a variety of defects. On the other hand, solid-state welding and diffusion bonding may not be suitable due to the presence of chemically stable surface layer of aluminium oxide, which, being insoluble in aluminium, inhibits metal-to-metal contact during diffusion bonding. Furthermore, diffusion bonding requires a very smooth and clean contact surface, which is difficult to obtain in industrial applications. As an alternative, transient liquid phase (TLP) diffusion bonding, which operates at a lower temperature, can be used to circumvent the problems associated with the oxide layer. The formation of liquid phase (eutectic) can assist the disruption of the oxide layer and promote metallic contact. The composite material used in the present study consisted of 6061 alloy containing 15 volume % of SiC particulates of 23 μm diameter. TLP bonding was carried out at 560 C in argon atmosphere using copper as an interlayer with different pressures and holding times. TLP-bonded AlMMCs were characterized by optical and scanning electron microscopy, microhardness survey, and shear tests. The results indicated that adequate bond strength could be achieved with suitable bonding parameters such as holding time and initial pressure. [ABSTRACT FROM AUTHOR]

Staining of tissues by dyes is accomplished through various types of bonds, some of which have been poorly defined in traditional biological literature. Here, basic principles of bonding are reviewed to establish uniform terminology and definitions consistent with the field of chemistry. The concept of charge – its presence or absence, magnitude, extent of delocalization and potential for being displaced by outside forces – underlies all bonding phenomena. These same attributes influence solubility and resistance to extraction during dehydration of tissue sections. Covalent bonds involve shared electrons; they are very strong and essentially irreversible under conditions encountered during staining. Polar covalent bonds within dye molecules generate partial atomic charges that create the potential for hydrogen bonding. This is measured by the hydrogen bonding parameter ( h ), the number of groups bearing charges within the ranges -0.15 to -0.50 eV or +0.15 to +0.30 eV. The potential for ionic bonding is indicated by net charge ( Z ), while the strength of such bonds is a function of charge site geometry on both bonding partners. Charge delocalization owing to conjugation, electron influencing groups, and resonance creates soft charge sites in which the ionic charge is spread over a large volume. Poorly delocalized charges or point charges are hard (small in volume). Firm bonds result from hard-hard or soft-soft pairs. Hard-soft combinations are weak, readily displaced in competitive interactions, and disrupted by solvents. Coordinate bonds with certain metals are involved with mordant staining and metal chelation dyes. Three different van der Waals attractions comprise the remainder of bonding types, all involving dipoles: Keesom (dipole-dipole) forces, Debye (dipole-induced dipole) forces and London (induced dipole-induced dipole) forces. Potentials for engaging in any of these is quantified by measures of polarity (dipole moment, d ), polarizability (crudely with π atoms describing the size of the conjugated system, or more directly with α ), hydrophobicity (with the octanol-water partition coefficient, log P or the more convenient Hydrophobic Index, HI ), and the number of halogen atoms ( X ). By using molecular modeling software, quantitative measures of bonding potential (bonding parameters) have been determined for over 400 dyes. [ABSTRACT FROM AUTHOR]

In this paper, the static and dynamic torque capacities of the cocured joints were observed with respect to several bonding parameters such as surface roughness, bonding length and stacking angle and compared with those of conventional adhesively bonded joints. In order to analyze the stresses of the cocured joint, finite element analysis was performed incorporating the nonlinear shear behavior of epoxy resin. The dependence of the static torque capacities on the bonding parameters was investigated numerically. [ABSTRACT FROM PUBLISHER]

ESR and optical absorption studies are described for a number of copper(II) single and mixed ligand complexes formed with substituted salicylic acids and acetylacetone. ESR spectra of all these complexes give well-resolved spectra in DMF both at room and liquid nitrogen temperatures. The molecular orbital coefficients are estimated assuming an axial symmetry. A partial covalency is observed in all the single ligand complexes while the in-plane π-bonding is as strong as the σ-bonding in all the mixed ligand complexes. No regular trend is observed in the value of χ (which is proportional to hyperfine constants) with the change in the overall electron withdrawing capacity of the substituent on salicylic acid, either in single ligand or in mixed ligand complexes. However, the χ values for all the complexes (except in the case of bis(acetylsalicylato)copper(II) and (acetylacetonato)-(3,5-dinitrosalicylato)copper(II)) are in agreement with the computed value of χ = −3.61 for single crystals of copper-acetylacetonate possessing the same environment of four oxygens around copper(II). [ABSTRACT FROM AUTHOR]

Single crystal EPR spectra of a natural mineral, apophyllite, containing VO(II) ion as an impurity have been investigated. The EPR spectra of the mineral, as obtained, was complex in nature, but was simplified by annealing the crystals at 490 K. The EPR parameters of the VO(II) species in the annealed crystal, g = 1.924 (2); g = 1.983 (2); A = 18.35 (5); and A = 7.24 (5)mT, are very close to a typical VO(II) impurity. Theoretically calculated line positions, using second-order hyperfine terms in the spin Hamiltonian with an axially symmetric g and A tensor values, agreed very well with the experimental ones. The EPR analysis of the annealed crystal has further revealed that the most preferred location of the VO(II) impurity is a substitutional Ca(II) site. The calculated bonding parameters and admixture coefficients indicate a fair amount of covalent bonding in the complex. [ABSTRACT FROM AUTHOR]